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A subsidiary of

Millennium Technologies Parent Company


HOME » Crankshaft Service


V-Twin cranks are built heavy, but can easily become out of balance from even standard use. This misalignment causes excessive vibrations and shaking, loss of power, and greatly decreases main bearing life. Loud noise from the crank case can be caused by a scissoring condition (when flywheel halves are no longer aligned) which is very common among used engines. Additionally, excessive play in connecting rods can also lead to catastrophic failures. A trued, welded, and balanced crank is more efficient, increases power, and runs smoother. Taking good care of your bottom end will extend surrounding components’ life expectancy, so more time on the road and less time in the shop! Remember: ALWAYS balance your crankshaft when increasing displacement!!


When adding big bore pistons, especially extremely big bore pistons like our Monster Big Bore Kits, the increase in reciprocal mass (rods and pistons) dictates balancing the rotational mass, the crankshaft. The crank is completely disassembled and trued. The crank is then dynamically balanced on our ultra-precise Sunnen DCB750 dynamic balancing machines. A plug is then inserted and the welded in place, so the crank will remain balanced and true. A properly balanced crank will make more power with increased reliability.


Pressed together Harley-Davidson EVO cranks are often out of true even as new. Over time they can move and become even more out of true. This can cause excessive vibration, less power, and damage to the oil pump and cam plate. Revolution Performance Basic Service can fix this common issue and help to prevent it from happening again. We true the crank, insert a plug, and then weld the crank pin to help prevent movement.

For more information or to order crankshaft service packages, please contact us direct at: 1-866-892-2109

Price subject to change without notice